Electrical power meters (EPMs) are widely used in residences and businesses to measure power consumption. Electrical power meters are also known as watt-hour meters. Countries such as India, China, Turkey and other populous countries that are quickly industrializing desire many EPMs to connect to the newly developing power grids. Additionally, other more industrialized countries are moving from mechanical power measuring devices to electronic devices in order to measure power more effectively.
Due to the large number of power meters being installed, this market has become very cost conscious, so much so that the power meters have basically become a “commodity”. In particular, in developing countries, cost is a major factor in the decision to choose a power meter. As such, it is very desirable to make the power meter as inexpensive as possible.
Conventional power meters may need to support a range of current loads from 10 amperes (A) to over 200 A depending upon the accuracy requirement. Conventional power meters generally utilize a dedicated 12-bit, 14-bit or 16-bit analog-to-digital converter (ADC). Additionally, some conventional power meters use multiplexing to measure more than one channel of data. The processing operations typically required to produce the energy measurement are generally performed using a 16-bit processor or digital signal processor (DSP), or a custom application-specific integrated circuit (ASIC).
One of the disadvantages of using a 12-bit, 14-bit or 16-bit ADC is that it typically involves utilizing a high bandwidth processor or DSP in order to manage the sampling rate, which adds additional cost in making the conventional power meter. Furthermore, utilizing a 12-bit, 14-bit or 16-bit ADC can increase the conventional power meter fabrication costs. It is noted that if a custom ASIC is utilized, another microprocessor is typically needed to provide energy management and communication features, thereby adding cost and complexity to the conventional power meter. Moreover, conventional power meters are usually not dynamically scalable.
The invention may address one or more of the above issues.